Abstract
The efficiency of pediatric left ventricular assist centrifugal blood pump is about 10％ or less at 0.5 /min. It is important
to improve efficiency and to prevent blood trauma. However, the improvement of the efficiency of a centrifugal blood
pump is difficult, because the specific speed is low and the viscosity of the working fluid is about four times water. In general,
a positive displacement pump is suitable for the low specific speed. However, when the enclosed chamber is formed in
the pump, the red blood cell might be destroyed in the contact point of a rotor and a stator. In this research, a single screw
blood pump which has narrow gap between a rotor and a stator was designed to prevent blood trauma. The fundamental
performance such as leakage and pump characteristic was investigated, and it was found that this pump has enough performance
for assisting infant left ventricular.
